National Geographic : 1892 Mar 21
II. F. Reid-Studies of Muir Glacier. interpretation of Vancouver's description seems perfectly in ac cord with what our observations would lead us to conclude. The retreat is probably not regular but faster some years than others, and even varies considerably at different parts of the same season. For two or three weeks in August, 1890, there was scarcely any fall of ice; in the two weeks following the fall was so rapid that a great bay fully a quarter of a mile deep was made in the eastern part of the ice-front, which was before this only slightly concave. Plate 13, from a photograph taken on Sep tember 7, 1890, shows this indentation. I have collected on the map (plate 15) the positions of the ice-front at several periods; this shows the retreat at a glance much better than it can be de scribed in words. The changes in the shape of the front will also be evident. The present rate of recession of the ice-front in Muir inlet, a mile in seven years, will probably be exceeded in the near future; for it has reached a point where the conditions change. The de posits which support the wings are almost at the water level at the ice-front, and slope down at an angle of 6° or 70; a little further back they will be below the water level and the ice-front will be broader, resulting in an increased amount of loss by breakage and hence a more rapid retreat. Ten or 15 years will probably see Dirt glacier on the east and the western tributary on the west entirely separate from the main ice stream. Dying glacier is rapidly disappearing; in 15 or 20 years I think its bed will be empty. The maps I have made will enable us to determine with considerable accuracy the amount of these changes in the future. I should, however, say that although the northern end of Main lake is in its right place, the southern end is only approximately determined. The ends of Dying glacier are also only approximate.* * Note added November, 1891. From photographs and descriptions sent me by Miss E. R . Scidmore I find that there have been some changes in the ice-front in the past year. The northwestern corner seems to have advanced slightly; the northeastern corner has receded 50 or 100 yards, and the rest of the front, which is nearly a straight line, has retreated some 300 yards since July 26, 1890. It is not, however, quite so far back as the extreme end of the bay formed just before we left in 1890. The stream which issued from the ice at the northeastern corner now comes out from under the wing and rushes across the beach, which it thus sepa rates from the ice-front. The large glacial stream on the east will undoubt edly follow the channel of this stream before long and fulfill Professor Wright's prophecy (Ice Age in North America, p. 54).
1892 May 15
1892 Feb 19